Method for controlling the filling or weighting absorption of a fibrous material

ABSTRACT

METHOD OF CONTROLLING ABSORPTION OF A FILLING AGENT BY A FIBROUS MATERIAL INCLUDES APPLYING A CONSTANT ESCESSIVE CONCENTRATION OF FILLING AGENT TO THE FIBROUS MATERIAL, PASSING THE THUS-FILLED FOBROUS MATERIAL BETWEEN A PAIR OF SQUEEZE ROLLERS AND SIMULTANEOUSLY INCREASING THE BEARING PRESSURE OF THE SQUEEZE ROLLERS TO A GIVEN OPTIMIUM VALUE IN DEPENDANCE UPON THE AMOUNT OF FILLING AGENT ABSORBED, AND, AFTER THE OPTIMUM BEARING PRESSURE IS ATTAINED, VARYING THE CONCENTRATION OF THE FILLING AGENT TO   THEREBY REGULATE THE ABSORBED AMOUNT, AND APPARATUS FOR CARRYING OUT THE FOREGOING METHOD.

June 5, 1973 H. KABELITZ 3,737,338

METHOD FOR CONTROLLING THE FILLING OR WEIGHTING ABSORPTION OF A FIBRQUSMATERIAL Original Filed Sept. n, 1968 United States Patent Int. or. nose11/10 US. Cl. 117-102 L 4 Claims ABSTRACT OF THE DISCLOSURE Method ofcontrolling absorption of a filling agent by a fibrous material includesapplying a constant excessive concentration of filling agent to thefibrous material; passing the thus-filled fibrous material between apair of squeeze rollers and simultaneously increasing the bearingpressure of the squeeze rollers to a given optimum value in dependenceupon the amount of filling agent absorbed; and, after the optimumbearing pressure is at tained, varying the concentration of the fillingagent to thereby regulate the absorbed amount; and apparatus forcarrying out the foregoing method.

This application is a continuation of application Ser. No. 758,477,filed on Sept. 9, 1968, now abandoned, and relates to method andapparatus for controlling or regulating the filling or Weightingabsorption of a fibrous material.

To control the filling or weighting absorption of a fibrous material, ithas been known heretofore to vary either the bearing pressure of thesqueeze rollers between which the fibrous material is passed or theconcentration of the filling or weighting agent in dependence upon themeasured filling or weighting absorption. When controlling the fillingor weighting absorption by varying the bearing pressure of the squeezerollers, it has been found, however, that the bearing pressure of thesqueeze rollers cannot be increased arbitrarily. On the one hand,consideration must be given to the fact that with a squeeze pressurethat is too high, burls, nubs or snarls can be impressed and crushed orcrumpled. The surface of the squeeze rollers can be damaged and the nipor squeeze gap between the rollers can be so widened that an undesiredhigh wet-stretching of the fibrous material being processed thus occurs.Furthermore, in such a case, it is essential that a filling operation beperformed, which unnecessarily burdens the running of the machine. Onthe other hand, consideration must also be given to the fact that, afterexceeding a given limit of the squeeze pressure, upon further increasein the squeeze pressure, the squeeze effect will vary onlyinsignificantly until it will finally remain unchanged. From theseconsiderations there results an optimum value for the squeeze pressure.In order to ensure a sufliciently Wide control range of the bearingpressure of the squeeze rollers below this optimum value Whencontrolling the filler absorption by varying this bearing pressure, itis necessary to select the concentration of the filling agent at asomewhat lower value than is desirable for optimum squeezing. However,such a step is disadvantageous in that the drying device through whichthe thus-filled fibrous material subsequently passes must apply greaterpower in order to remove the increased moisture content from the fibrousmaterial. On the other hand, the control of the filling absorption byvarying the concentration of the filler agent has the disadvantage that,initially, the squeeze pressure must be preselected. In order ice tomaintain the drying power output of the drying device, to which thefilled fibrous material is thereafter passed, at the smallest possiblevalue, it is therefore desirable to adjust the bearing pressure of thesqueeze rollers to a given optimal value. Heretofore, attention has beendirected for this purpose to experimental and empirical values, with dueconsideration having to be given to the type of fibrous material beingprocessed, especially the filler absorption capacity thereof. With thenew types of fibrous material, particularly the man-made fibers, thisautomatically necessitates the maintenance of an excessive safety zoneor margin which can be reduced only in the course of time and on thebasis of accumulated experience. Naturally, in the time necessary forobtaining the required knowledge, considerable loss in processingactivity is sustained.

' It is accordingly an object of my invention to provide method andapparatus for controlling the absorption of filler by a fibrous materialwhich avoid the foregoing disadvantages of the heretofore known methodsand apparatus of this general type.

With the foregoing and other objects in view, I provide method ofcontrolling the absorption of filler agent by a fibrous material whichcomprises applying a constant excessive concentration of filling agentto the fibrous material; passing the thus-filled fibrous materialbetween a pair of squeeze rollers and simultaneously increasing thebearing pressure of the squeeze rollers to a given optimum value; and,after the optimum bearing pressure is attained, varying theconcentration of the filling agent.

The servicing personnel are thus not advised of any experimental data orvalues, but rather, they begin the processing of the fibrous materialinitially with a filling material concentration which, based uponexperience even for optimum value of the squeeze roller bearingpressure, will nevertheless produce too great a filling of the fibrousmaterial. This procedure is followed because excessive filling isgenerally considerably less damaging in the further processing of thefibrous material than is a filling that is too low for the fibrousmaterial. Then, the bearing pressure of the squeeze rollers is increasedin dependence upon the filling absorption for as long as a furtherincrease in the bearing pressure will only result in an insignificantchange in the filling absorption. The optimum value of the bearingpressure is simultaneously attained therewith. Thereafter, theconcentration of the filling agent can be varied in a conventionalmanner in accordance with the filling absorption. During this controloperation it can be advantageous, in accordance with the invention, tovary the bearing pressure in a conventional manner in accordance withthe flowthrough rate or throughput of the fibrous material, when thethroughput is required to be changed, for example by a switchover toslow or creeping motion.

The apparatus for carrying out the method of my invention comprisesmeans for varying the bearing pressure of the squeeze rollers, means forvarying the concentration of the processing medium supplied to theprocessing vessel, means for measuring the filling absorption in thefibrous material to which the filling agent is applied, and switch meansconnected between the measuring means, on the one hand, and the bearingpressure varying means and the concentration varying means, on the otherhand, for initially increasing the bearing pressure to a given optimalvalue thereof in dependence upon the measured value of the fillingabsorption, and thereafter automatically controlling the concentrationto an adjustable nominal value in dependence upon the measured value ofthe filling absorption.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as method andapparatus for controlling the filling or weighting absorption of afibrous material, it is nevertheless not intended to be limited to thedetails shown, since various modifications may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims.

The invention, however, together with additional objects and advantagesthereof Will be best understood from the following description when readin connection with the accompanying single figure of the drawing whichshows diagrammatically the apparatus for carrying out the method ofcontrolling the absorption of filling agent by a fibrous material.

Referring now to the figure, there is shown a processing vessel 1containing a filling or weighting agent, in the instant case a sizingsolution, through which a fibrous material, a warp thread bunch F in thecase at hand, is passed by means of immersion rollers 2 in aconventional manner. Furthermore, the thread bunch F is conveyed, in amanner well known in the art, over deflecting rollers 3 and between apair of squeeze rollers 4. In the processing vessel 1 containing thesizing, there is provided an overflow vessel 1a in a constructionheretofore well known, the sizing being supplied by means of a pump 5continually in excess quantity to the processing sizing vessel 1. Ameasuring or test probe 6 is disposed within the overflow vessel 1a toestablish the fluid level therein which, after dropping below apredetermined level of the bath, achieves renewed filling of theoverflow vessel 1a. Furthermore, the deflecting or diverting roller 3 isfurnished with a measuring or testing device for establishing the lengthof the thread bunch which has passed by the same. In the embodimentillustrated in the figure, this lentgh measuring device includes a pulsegenerator 7 which generates a pulse that affects an indicating devicewhich registers the length in suitable units of the fibrous materialwhich has passed by. To provide a refill for the expended sizing liquid,the overflow vessel 1a is connected through a conduit '8, in which thereis provided a valve 8a which is either operable by hand or by remotecontrol, with a metering and mixing vessel 9. A source bath or liquid ofconstant concentration is supplied from the heating or supply vessel 11to the metering and mixing vessel 9 in a conventional manner through theconduits 10 and the valve 10a disposed therein. In order to achieve thedesired concentration in the sizing vessel 1, a diluent or dilutingliquid is supplied to the metering and mixing vessel 9, moreover,through the conduit 12 in which a control valve 12a is connected. Toensure the desired bath temperature, the metering and mixing vessel 9 isprovided with direct steam heating by any suitable conventional means,the supplied heating steam being directly blown into the sizing solutioncontained in the metering and mixing vessel 9 through a conduit 13 inwhich a Valve 13a is connected. As can be seen in the figure, a stirringdevice 14 extends into the metering and mixing vessel 9 and is driven bya motor 15 located outside the vessel, so as to intimately intermix thesource bath with the diluent. Additionally extending into the meteringand mixing vessel 9 is a temperature sensing element 16 as well as aliquid level test probe having contacts 17 and 1 8 for respectivelysensing a minimum and maximum liquid volume located in the metering andmixing vessel. There is also provided a test probe adjustable by a motor19 and having as its function the determination, in a conventionalmanner, of the mixing ratio of the source sizing, supplied from theheating or supply vessel 11, to the diluent supplied through the conduit12. The bearing pressure of the squeeze rollers 4- is produced byconventional of the squeeze rollers 4 can be read directly from amanometer 23 connected in the pneumatic line terminating in the cylinder21.

All of the sensing and control leads connect with a switching device 24.A main switch 25 is provided in the switching device 24 and connects theentire system through a line 26 with the utility line. There isfurthermore provided a selector switch 27 as well as an indicatinginstrument 2 8 which are connected to the pulse generator 7 and indicatethe length of the warp thread bunch F that has run past the pulsegenerator 7. In addition, two push buttons 29 and 30 are provided bymeans of which the adjusting motor 19 for the test probe 20 can beswitched on in one or the other rotary direction so as to move the testprobe 20 in an upward or downward direction respectively. Therewith, therespective push button is simultaneously illuminated, and quiteindependently of the fact whether the switching on of the motor 19 iselfected by actuation of the respective push button or automatically.Two signal lamps 31 and 32 of diflerent color, if necessary, are alsoprovided, one of which being able to be switched on by the measuringprobe 6 and the other by the indicator device 28. Since it is arelatively simple matter for an electrician to suitably wire theforegoing components of the switching device 24 and since it is believedthat a showing of the Wiring of those members in the figure mightsomewhat obliterate other important details and might lead to possibleconfusion, the exact wiring of the components to one another is notshown in the drawing.

The method of my invention is carried out with the illustrated apparatusin the following manner.

Before the beginning of the sizing operation, the sizing or processingvessel 1 and the overflow vessel 1a are filled with a sizing solution ofexcessive concentration. If, for example, a sizing concentration of 10%for the sizing vessel 1 is considered to be probably or presumablycorrect, the sizing vessel 1 is initially filled with a 12 or 15% sizingsolution. The selector switch 27 is then first set to control thebearing pressure of the squeeze rollers 4. For this purpose, the lengthof the thread bunch F which has run through the apparatus is comparedwith the consumption of sizing liquid in the sizing vessel 1 in a mannercorresponding, for example, to that of the Swiss Pat. 372,020. Since thesizing concentration in the vessel 1 is exceeded, the signal ProcessingLiquid Consumed is given by the liquid level measuring probe 6 soonerthan the measured length predetermined for the nominal amount of sizingsensed by the pulse generator 7 appears at the indicating instrument 28.In this case the indicator lamp 31 is switched on by the test probe 6and is illuminated, there by indicating that too much sizing has beenapplied to the thread bunch "F. Simultaneously, the switching device 24issues an adjusting pulse to the valve 22 to increase the bearingpressure of the squeeze rollers 4. This operation is repeated until noessential change in the length is produced any longer for repeatedindications at the measuring device 28. The value of the bearingpressure of the squeeze rollers 4 indicated at the manometer 23 thencorresponds to the optimum value of the squeezing efiect or action.

Depending upon the composition of the squeeze rollers 4 and of thematerial being processed, the optimum value of the bearing pressure can,however, also be lower than the optimum value of the squeeze effect oraction established in the aforedescribed manner. As has been mentionedbefore, consideration must also be given, with regard to the optimumvalue of the bearing pressure, to the fact that for squeezing pressurewhich is too high, burls, nubs or snarls can be impressed and crushed orcrumpled, and with corresponding ring travellers on the rollers theroller surface can become damaged, and so forth. In case the therebyallowable optimum value of the bearing pressure is not known beforehand,the material to be processed, in this case the warp thread bunch F, mustbe inspected while the bearing pressure of the squeeze rollers 4 isbeing increased. Otherwise, it is sufficient to inspect the manometer 23and to interrupt the control operation for increasing the bearingpressure of the squeeze rollers 4 when attaining the indicated optimumvalue at the manometer 23.

When the optimum value of the bearing pressure of the squeeze rollers 4is attained, the-selector switch 27 is adjusted to the positionConcentration Control which then acts to change the concentration of thesizing solution supplied to the sizing or processing vessel 1 throughthe conduit 8. The following operation then takes place.

It is assumed that in the heating or supply vessel 11 a 20% source bathis always produced which-mixes with the diluent supplied through theconduit 12 in the metering and mixing vessel 9 in such a ratio that theuseful sizing supplied through the conduit 8 attains the concentrationcorresponding to the degree of sizing of the warp thread bunch F. Forthis purpose, the valve 10a is initially opened and so much of thesource bath is supplied to the metering and mixing vessel 9 from theheating or supply vessel 11 until the adjustable test probe suitablyresponds. The valve 10a is then closed and the valve 12a is opened,which then permits the metering and mixing vessel 9 to be filled untilthe maximum contact 18 of the liquid level measuring device suitablyresponds thereto.

Since, with the aforedescribed method of my invention, the useful sizingsupplied through the conduit 8 to the sizing vessel 1 should initiallyexhibit an excessive concentration so that even for optimum bearingpressure of the squeeze rollers 4 the test probe 6 should respond soonerthan the measuring device 28 registers the nominal length of the threadbunch passing through the apparatus, the indicator lamp 31 connectedwith the test probe 6 will become illuminated sooner than the indicatorlamp 32 connected with the measuring device 28 also after the selectorswitch 27 is switched over to the position Concentration Control.Simultaneously, adjusting pulses are passed from the switching device 24to the motor 19 for the probe 20 for a period of time until theindicator lamp 32 also becomes illuminated i.e. until the value of thenominal measured length of the thread bunch passing through theapparatus is also registered at the measuring device 28. Accordingly,the adjusted level of the probe 20 is higher the greater the timedifference between the response of the test probe 6 and the attainmentof the value of the nominal measured length at the measuring device 28.The deeper the adjustable probe 20 is immersed in the metering andmixing vessel 9, the less source bath is supplied through the conduit 10so that all the more diluent is supplied through the conduit 12 to fillthe metering and mixing vessel 9. The concentration is thus the moresharply reduced the deeper the adjustable probe 20 is immersed. If itshould happen thereby that the concentration should drop slightly belowthe nominal value so that the indicated measured length of the measuringdevice 28 attains its nominal value sooner than the test probe 6responds, the indicator lamp 32 then is illuminated first.Simultaneously, adjusting pulses are transmitted to the adjusting motor19 for the probe 20 in a direction so that the probe 20 is immersed lessdeeply in the vessel. Also here the adjusting pulses are again generatedduring the entire time difference between the response of the meterindicator of the measuring device 28 and the response of the test probe6.

In principle then, according to the method of my invention, the amountof filling agent absorbed by a fibrous material from a solution of thefilling agent is regulated to a predetermined so-called nominal or datumvalue whereby the specific amount of filling agent corresponding to thenominal or datum value remains in the fibrous material. Thus, forexample, in filling a thread bunch with a starch sizing, the quantity ofsizing remaining in the thread bunch is maintained constant at aspecific value clear that the greater the bearing pressure applied bythe squeeze rollers, the smaller is the amount of sizing absorbed.Furthermore, the absorbed amount of sizing is also dependent upon theconcentration of the sizing solution. The higher the concentration, i.e.the greater the quantity of sizing contained in the water, the greateris the amount of sizing remaining in the thread after the Water isremoved therefrom. Since the amount of squeezing action effected by thesqueeze rollers is approximately known, the concentration of thetreating agent, i.e. the sizing solution, can be predeterminedapproximately in order to obtain a specific filling absorption, i.e. tosize the fibrous material to a specific degree.

According to the method of the invention, therefore, I employ anexcessive concentration of the filling agent, i.e. of the sizingsolution, and initially maintain that concentration at a constant value.Since the measuring device which measures the amount of fillingabsorbed, naturally indicates an excessive filling absorption quantity,the bearing pressure of the squeeze rollers is first increasedautomatically in dependence upon this indicated filling absorptionquantity until the optimum value of the bearing pressure is attained,which can be indicated, for example, at the device for measuring theamount of filling absorbed, that measuring device indicating no furtherdecrease in the amount of filling agent absorbed. The concentration ofthe filling agent is thereafter reduced in dependence upon the measuringdevice reading or indication of the amount of filling agent absorbeduntil the actual value indicated by the measuring device corresponds tothe nominal or datum value of the desired filling absorption, so thatthe fibrous material has thus actually absorbed that amount of fillingagent that it should have absorbed.

Thus, in the method of my invention as well as in the apparatus forcarrying out the method, there is employed a genuine regulating systemwith an actual closed regulating circuit containing an actual valueindicator and a nominal or datum value producer or indicator, as isknown particularly from regulating methods in electrical technology.

As has been repeatedly noted, the invention is not limited to theparticular embodiment disclosed hereinbefore and illustrated in thedrawing. For example, to establish the actual value of the fillingabsorption, instead of comparing the measured length of the thread bunchF passing through the apparatus with the consumption established at thefluid level test probe 6, other testing or measuring methods can beemployed to provide an accurate reference point for the actual value ofthe sizing absorption by the thread bunch F.

I claim:

1. Method of controlling absorption of a filling agent by a fibrousmaterial, which comprises applying a constant excessive concentration offilling agent to the fibrous material; passing the thus filled fibrousmaterial between a pair of squeeze rollers and simultaneously increasingthe bearing pressure of the squeeze rollers to a given optimum value independence upon the amount of filling agent absorbed by the fibrousmaterial; and, after the optimum bearing pressure is attained, varyingthe concentration of the filling agent to thereby regulate the amountabsorbed by the fibrous material.

2. Method according to claim 1 wherein the bearing pressure of thesqueeze rollers is varied by varying the rate at which the fibrousmaterial is passed through the nip between the rollers.

3. Method according to claim 1 wherein the filling 7 agent is applied tothe fibrous material by passing the latter through a bath of the fillingagent.

4. Method according to claim 1 wherein the concentration of the fillingagent is reduced after the optimum bearing pressure is attained.

References Cited UNITED STATES PATENTS 8 3,292,573 12/1966 Jones 118-73,425,861 2/1969 Jones 117-102 L FOREIGN PATENTS 614,045 2/1961 Canada118-7 654,178 6/1951 Great Britain 118-7 907,529 10/1962 Great Britain11s 7 ALFRED L. LEAVI'IT, Primary Examiner I. R. BATIEN, IR., AssistantExaminer US. Cl. X.R. 1l7102 A, 102 R; 1187 Inventor g I cercif Led thaterror appears in the above-identified patent (ma hat said Letcers Pate tare hereby corrected as shown below:

' E In I the heading to the printed specification, Line 12,

"s 111,702" should read --s 111 7o2'vI1a/8a" Signed-endsealed this 25thday of December 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer AetingCommissioner of Patents

